"CAL" is Swarovski's abbreviation for "comet argent light" which is a vacuum metal coating applied to the surface of the stone producing a bright, mirror-like effect. The "V" stands for "reverse," meaning the surface effect has been used as a translucent effect, applied only to the back of the stone. "SI" means the component has a foil backing. The result is a striking crystal component with vivid flash and intensified color.